bioRxiv Science⌕ Search

Biology subjects

Phillips, A. H.

Publications and source records attributed to Phillips, A. H..

2 recordsLinked to original sources

Proteome-wide computational analyses reveal links between protein condensate formation and RNA biology

Biomolecular condensates mediate dynamic compartmentalization of cellular processes. The multivalent interactions that underlie biomolecular condensation are often promoted by intrinsically disordered regions (IDRs) within proteins. While the role of IDRs in biomolecular condensates is well appreciated, predicting whether an IDR forms condensates in cells remains challenging. Here, we developed a machine learning model to predict condensation behavior of IDRs, analyzing 215 IDRs from fusion oncoproteins in HEK293T cells. Our study identified distinct sequence-derived physicochemical features associated with condensation. Leveraging these data, our model predicts that [~]12% of the [~]13,000 IDRs in the human proteome are likely to form cellular condensates. Proteins with condensate-forming IDRs are enriched in functions involving RNA-related processes and membrane-less organelles (MLOs), highlighting their role in MLO assembly and function. Our model, available via the SAK3.0 web server (https://sak.stjude.org), provides a powerful resource for studying IDR-driven phase separation across proteomes, offering insights into biomolecular condensates and their biological roles.

bioinformatics↗

Biomolecular condensates form spatially inhomogeneous network fluids

The functions of biomolecular condensates are thought to be influenced by their material properties, and these will be determined by the internal organization of molecules within condensates. However, structural characterizations of condensates are challenging, and rarely reported. Here, we deploy a combination of small angle neutron scattering, fluorescence recovery after photobleaching, and coarse-grained molecular dynamics simulations to provide structural descriptions of model condensates that are formed by macromolecules from nucleolar granular components (GCs). We show that these minimal facsimiles of GCs form condensates that are network fluids featuring spatial inhomogeneities across different length scales that reflect the contributions of distinct protein and peptide domains. The network-like inhomogeneous organization is characterized by a coexistence of liquid- and gas-like macromolecular densities that engenders bimodality of internal molecular dynamics. These insights suggest that condensates formed by multivalent proteins share features with network fluids formed by systems such as patchy or hairy colloids.

biophysics↗